China announced a sharp rise in its monthly trade surplus in October, thanks to booming exports, while the U.S. trade deficit with China increased in September to a record $20.10 billion. The developments are likely to escalate pressure on Beijing to make its currency exchange rate more flexible ahead of a visit by U.S. President George W. Bush.

However, China's central bank Thursday ruled out allowing another sudden appreciation of the yuan against the dollar similar to one in July, when the yuan was revalued by 2.1%. And...